Title: Punching Shear Strength of Post-Tensioned Ultra-High- Performance Concrete Plates

Author(s): Mehmet Dogu and Fatmir Menkulasi

Publication: Structural Journal

Volume: 119

Issue: 3

Appears on pages(s): 165-178

Keywords: finite element analysis; load-rotation relationship; moment curvature; post-tensioning; punching shear; ultra-high-performance concrete (UHPC); unbonded tendons

DOI: 10.14359/51734436

Date: 5/1/2022

Abstract:
A method to predict the punching shear capacity of ultra-high-performance concrete (UHPC) plates post-tensioned (PT) with internal unbonded tendons is presented. The method simultaneously supplies a plate’s punching and rotation capacity by superimposing a plate’s load-rotation relationship and a rotation-dependent failure criterion. The derivation of plates’ load-rotation relationship is based on engineering mechanics and is informed by the moment-curvature response of an equivalent plate of unit width. Criteria are presented for distinguishing between punching and flexural failures in numerical and prediction models. Validated nonlinear finite element models are used to create a database of punching-critical PT UHPC plates, which is used to derive a nonlinear regression-based failure criterion. The impact of column size, plate thickness, prestressed and non-prestressed reinforcement ratio, tendon configuration, prestressing force, and fiber content and characteristics on plate punching shear capacity is quantified.